Use of hydroxocobalamin to treat intraoperative vasoplegic syndrome refractory to vasopressors and methylene blue during liver transplantation.

INTRODUCTION: For patients with catecholamine-resistant vasoplegic syndrome (VS) during liver transplantation (LT), treatment with methylene blue (MB) and/or hydroxocobalamin (B12) has been an acceptable therapy. However, data on the effectiveness of B12 is limited to case reports and case series. METHODS: We retrospectively reviewed records of patients undergoing LT from January 2016 through March 2022. We identified patients with VS treated with vasopressors and MB, and abstracted hemodynamic parameters, vasopressor requirements, and B12 administration from the records. The primary aim was to describe the treatment efficacy of B12 for VS refractory to vasopressors and MB, measured as no vasopressor requirement at the conclusion of the surgery. RESULTS: One hundred one patients received intraoperative VS treatment. For the 35 (34.7%) patients with successful VS treatment, 14 received MB only and 21 received both MB and B12. Of the 21 patients with VS resolution after receiving both MB and B12, 17 (89.5%) showed immediate, but transient, hemodynamic improvements at the time of MB administration and later showed sustained response to B12. CONCLUSION: Immediate but transient hemodynamic response to MB in VS patients during LT supports the diagnosis of VS and should prompt B12 administration for sustained treatment response.

Comparison of onset of neuromuscular blockade with electromyographic and acceleromyographic monitoring: a prospective clinical trial.

BACKGROUND: Reliable devices that quantitatively monitor the level of neuromuscular blockade after neuromuscular blocking agents' administration are crucial. Electromyography and acceleromyography are two monitoring modalities commonly used in clinical practice. The primary outcome of this study is to compare the onset of neuromuscular blockade, defined as a Train-Of-Four Count (TOFC) equal to 0, as measured by an electromyography-based device (TetraGraph) and an acceleromyography-based device (TOFscan). The secondary outcome was to compare intubating conditions when one of these two devices reached a TOFC equal to 0. METHODS: One hundred adult patients scheduled for elective surgery requiring neuromuscular blockade were enrolled. Prior to induction of anesthesia, TetraGraph electrodes were placed over the forearm of patients' dominant/non-dominant hand based on randomization and TOFscan electrodes placed on the contralateral forearm. Intraoperative neuromuscular blocking agent dose was standardized to 0.5 mg.kg-1 of rocuronium. After baseline values were obtained, objective measurements were recorded every 20 seconds and intubation was performed using video laryngoscopy once either device displayed a TOFC = 0. The anesthesia provider was then surveyed about intubating conditions. RESULTS: Baseline TetraGraph train-of-four ratios were higher than those obtained with TOFscan (Median: 1.02 [0.88, 1.20] vs. 1.00 [0.64, 1.01], respectively, p < 0.001). The time to reach a TOFC = 0 was significantly longer when measured with TetraGraph compared to TOFscan (Median: 160 [40, 900] vs. 120 [60, 300] seconds, respectively, p < 0.001). There was no significant difference in intubating conditions when either device was used to determine the timing of endotracheal intubation. CONCLUSIONS: The onset of neuromuscular blockade was longer when measured with TetraGraph than TOFscan, and a train-of-four count of zero in either device was a useful indicator for adequate intubating conditions. CLINICAL TRIAL NUMBER AND REGISTRY: URL NCT05120999, https://clinicaltrials.gov/ct2/show/NCT05120999.

Comparison of onset of neuromuscular blockade with electromyographic and acceleromyographic monitoring: a prospective clinical trial

Abstract Background Reliable devices that quantitatively monitor the level of neuromuscular blockade after neuromuscular blocking agents' administration are crucial. Electromyography and acceleromyography are two monitoring modalities commonly used in clinical practice. The primary outcome of this study is to compare the onset of neuromuscular blockade, defined as a Train-Of-Four Count (TOFC) equal to 0, as measured by an electromyography-based device (TetraGraph) and an acceleromyography-based device (TOFscan). The secondary outcome was to compare intubating conditions when one of these two devices reached a TOFC equal to 0. Methods One hundred adult patients scheduled for elective surgery requiring neuromuscular blockade were enrolled. Prior to induction of anesthesia, TetraGraph electrodes were placed over the forearm of patients' dominant/non-dominant hand based on randomization and TOFscan electrodes placed on the contralateral forearm. Intraoperative neuromuscular blocking agent dose was standardized to 0.5 mg.kg−1 of rocuronium. After baseline values were obtained, objective measurements were recorded every 20 seconds and intubation was performed using video laryngoscopy once either device displayed a TOFC = 0. The anesthesia provider was then surveyed about intubating conditions. Results Baseline TetraGraph train-of-four ratios were higher than those obtained with TOFscan (Median: 1.02 [0.88, 1.20] vs. 1.00 [0.64, 1.01], respectively, p < 0.001). The time to reach a TOFC = 0 was significantly longer when measured with TetraGraph compared to TOFscan (Median: 160 [40, 900] vs. 120 [60, 300] seconds, respectively, p < 0.001). There was no significant difference in intubating conditions when either device was used to determine the timing of endotracheal intubation. Conclusions The onset of neuromuscular blockade was longer when measured with TetraGraph than TOFscan, and a train-of-four count of zero in either device was a useful indicator for adequate intubating conditions. Clinical trial number and registry URL NCT05120999, https://clinicaltrials.gov/ct2/show/NCT05120999.

Apneic Technique in Laryngotracheal Surgery.

Background Apneic oxygenation can be applied to select laryngotracheal procedures to improve operative visualization and avoid potential complications associated with intubation and jet ventilation.  Aims/objectives The authors sought to determine if apneic oxygenation using a high-flow nasal cannula could be used as a safe alternative airway management strategy for the duration of select laryngotracheal procedures. Methods Single institution, multi-site retrospective review of 38 adult (>18 years old) patients undergoing apneic oxygenation in the setting of various laryngotracheal procedures from January 2017 through January 2018. Humidified oxygen was delivered via a high-flow nasal cannula. The data was collected and analyzed using SAS version 9.4 (SAS Institute, Cary, NC). Results Twenty-four women and 14 men, mean age 60.0 years (SD 16.1; 36-89) and 70.1 years (SD 7.2; 56-81), respectively, underwent a mean total apneic time of 23.9 minutes (13-40). A statistically significant correlation existed between apneic time and minimum oxygen saturation (Pearson correlation coefficient 0.38; p=0.018). Twenty-one patients resumed spontaneous ventilation without the need for jet ventilation, mask ventilation, or placement of a definitive airway during the procedure.  Conclusions and significance Apneic oxygenation allows for extended periods of operating without the need for the placement of an endotracheal tube in patients undergoing general anesthesia for select laryngotracheal procedures.

Bayesian predictive probabilities: a good way to monitor clinical trials.

BACKGROUND: Bayesian methods, with the predictive probability (PredP), allow multiple interim analyses with interim posterior probability (PostP) computation, without the need to correct for multiple looks at the data. The objective of this paper was to illustrate the use of PredP by simulating a sequential analysis of a clinical trial. METHODS: We used data from the Laryngobloc trial that planned to include 480 patients to demonstrate the equivalence of success between a laryngoscopy performed with the Laryngobloc® device and a control device. A crossover Bayesian design was used. The success rates of the two laryngoscopy devices were compared. Interim analyses, computed from random numbers of subjects, were simulated. RESULTS: The PostP of equivalence rapidly reached the predefined bound of 0.95. The PredP computed with an equivalence margin of 10% reached the efficacy bound between 352 and 409 of the 480 included patients. If a frequentist analysis had been made on the basis of 217 out of 480 subjects, the study would have been prematurely stopped for equivalence. The PredP indicated that this result was nonetheless unstable and that the equivalence was, thus far, not guaranteed. CONCLUSIONS: Based on these interim analyses, we can conclude with a sufficiently high probability that the equivalence would have been met on the primary outcome before the predetermined end of this particular trial. If a Bayesian approach using PredP had been used, it would have allowed an early termination of the trial by reducing the calculated sample size by 15-20%.

Gastric emptying of "clear liquid drinks" assessed with gastric ultrasonography: a blinded, randomized pilot study.

BACKGROUND: Protein-containing liquids may delay gastric emptying and increase risk of aspiration. Commercial whey protein nutritional drinks (WPNDs) are advertised as "clear liquid nutritional drinks" and can be mistaken for protein-free, carbohydrate-based clear liquids. We used gastric ultrasonography to compare gastric emptying of a protein-free, carbohydrate-based clear liquid with that of a WPND in healthy volunteers. METHODS: We recruited 19 adult (age ≥18 years) volunteers with a body mass index less than 40 kg/m2 and without a history of diabetes mellitus, dysphagia, prior gastric surgery, or allergy to the ingredients of apple juice (AJ) or a WPND. After fasting for eight hours, the volunteers randomly received 474 mL of AJ or a WPND. Gastric ultrasonographic measurements were obtained at baseline and at 0, 30, 60, and 120 minutes after ingestion of the liquid. RESULTS: We enrolled 19 volunteers. At 120 minutes after consumption, volunteers who ingested a WPND had a larger estimated gastric volume (GV) than volunteers who ingested AJ (median [interquartile range], 101.3 [70.0-137.4] vs. 50.6 [43.9-81.8] mL; P=.08). By using the 2-sample t test and an α level of .05, we determined that the study had 40% power to detect a significant difference in GV. Future studies need to include 24 participants per group to detect a significant difference. CONCLUSIONS: Although consumption of a WPND was associated with a larger estimated GV in this pilot study, a larger study is necessary to conclude whether patients must fast longer than two hours after consumption of a WPND.

Ultrasound Assessment of Gastric Volume After Bariatric Surgery: A Case Report.

Gastric ultrasound is emerging as a tool that can be used to assess gastric content and volume in patients with an unknown fasting history. This information can impact the choice of anesthetic technique or the timing of surgery due to the presumed risk of aspiration. Currently, no data are available regarding the use of gastric ultrasound for patients who have had prior gastric operations, despite the increasing number of patients undergoing bariatric surgery. Our experience suggests that a patient with a prior Roux-en-Y gastric bypass may present with altered anatomy, rendering gastric ultrasound an ineffective technique to assess the volume of ingested food or liquid.

Intraoperative fluid restriction in hyperthermic intraperitoneal chemotherapy.

BACKGROUND: Multiple studies highlight the importance of liberal fluid administration in cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC). Over-resuscitation can delay recovery and wound healing. We report an intraoperative protocol that restricts fluid administration and minimizes morbidity. MATERIALS AND METHODS: Retrospective analysis of 35 patients that underwent CRS-HIPEC for curative intent under fluid restriction protocol from June 2015 to July 2017 was performed. Protocol consists of continuous infusion of vasopressin 0.02 units/h and maintaining urine output at 0.5 mL/kg/h via crystalloid and colloid. Endpoint was Clavien-Dindo ≥3 events within 30 d of CRS-HIPEC. RESULTS: Median age was 56 y; 71% were female. Malignancies treated: appendix (49%), colon (31%), and other (20%). Median peritoneal cancer index was 15, complete cytoreduction was achieved in 91% of patients. Median time for return of bowel function was 5 d, median length of hospital stay was 7 d. There were 28 bowel anastomoses. Median intraoperative crystalloid, colloid, and packed red blood cells were (1900, 1500, and 700 mL), respectively. Clavien-Dindo grade 3-4 events occurred in five patients. There were no deaths 30 d after surgery. CONCLUSIONS: A fluid restriction protocol appears to be safe and feasible in the setting of CRS-HIPEC for curative intent.

Fulminant hepatic failure after simultaneous kidney-pancreas transplantation: a case report / Insuficiência hepática fulminante após transplante simultâneo de rim-pâncreas: um relato de caso

Abstract We describe an unusual case of hyperacute hepatic failure following general anesthesia in a patient receiving a simultaneous kidney-pancreas transplant. Despite an aggressive evaluation of structural, immunological, viral, and toxicological causes, a definitive cause could not be elucidated. The patient required a liver transplant and suffered a protracted hospital course. We discuss the potential causes of fulminant hepatic failure and the perioperative anesthesia management of her subsequent liver transplantation.

Resumo Descrevemos um caso incomum de insuficiência hepática hiperaguda após a anestesia geral em uma paciente que recebeu um transplante simultâneo de rim-pâncreas. Apesar de uma avaliação agressiva das causas estruturais, imunológicas, virais e toxicológicas, uma causa definitiva não pôde ser identificada. A paciente precisou de um transplante de fígado que resultou em prolongamento da internação hospitalar. Discutimos as potenciais causas da insuficiência hepática fulminante e o manejo da anestesia no período perioperatório de seu subsequente transplante de fígado.

Safe administration of hyperbaric oxygen after bleomycin: a case series of 15 patients.

INTRODUCTION: Supplemental oxygen has been reported to cause pulmonary complications after bleomycin. We describe the safe administration of hyperbaric oxygen (HBO2) after bleomycin in 15 patients. METHODS: Paper and electronic records were reviewed for bleomycin-exposed patients at the Duke Center for Hyperbaric Medicine and Environmental Physiology from 1979 to 2010. RESULTS: Fourteen bleomycin-exposed patients received HBO2 at Duke under a special-precautions protocol. One was treated for DCS elsewhere. The protocol included: pretreatment evaluation; chest radiograph; spirometry; blood gases; a single, 2-atmospheres absolute (atm abs), 120-minute HBO2 treatment; and a gradual acceleration over one week to a twice-daily schedule contingent on clinical and laboratory findings. Bleomycin indications were: head-and-neck squamous cell carcinomas (11), Hodgkin's lymphoma (2), other carcinomas (2). HBO2 indications were: osteoradionecrosis (10), soft-tissue radionecrosis (3), DCS (1) and a provocative oxygen toxicity test for a military aviator (1). Total bleomycin doses ranged from 40 to 225u/m2 (mean +/- SD, 105 +/- 57) given in conjunction with other chemotherapies and/or radiation. Radiation was 63.3 +/- 31.72 Gy (mean +/- SD), none to the chest with the exception of one patient treated for DCS elsewhere. Other chemotherapies included: vinblastine (11), methotrexate (11), CCNU (6) cisplatinum (7), dacarbazin (2), Adriamycin (1), and vincristine (1). Median age at time of HBO2 was 52 years (range 22-77). Median bleomycin-to-HBO2 latency was 34 months (range 1-279). Three patients received HBO2 within six months, and seven patients received HBO2 within two years of their last bleomycin exposure. There were no adverse pre-to-post HBO2 changes in: arterial blood gases, spirometry, chest radiograph findings or clinical reports. There were no persistent post-HBO2 pulmonary complications on follow-up. Post-HBO2 data were available for 40%, 53%, 87% and 100% of these parameters respectively. DISCUSSION: Bleomycin and oxygen can individually cause acute pulmonary toxicity. However, evidence for increased long-term susceptibility based on their synergy may be overstated.

Is a mandatory intensive care unit stay needed after liver transplantation? Feasibility of fast-tracking to the surgical ward after liver transplantation.

The continuation of hemodynamic, respiratory, and metabolic support for a variable period after liver transplantation (LT) in the intensive care unit (ICU) is considered routine by many transplant programs. However, some LT recipients may be liberated from mechanical ventilation shortly after the discontinuation of anesthesia. These patients might be appropriately discharged from the postanesthesia care unit (PACU) to the surgical ward and bypass the ICU entirely. In 2002, our program started a fast-tracking program: select LT recipients are transferred from the operating room to the PACU for recovery and tracheal extubation with a subsequent transfer to the ward, and the ICU stay is completely eliminated. Between January 1, 2003 and December 31, 2007, 1045 patients underwent LT at our transplant program; 175 patients were excluded from the study. Five hundred twenty-three of the remaining 870 patients (60.10%) were fast-tracked to the surgical ward, and 347 (39.90%) were admitted to the ICU after LT. The failure rate after fast-tracking to the surgical ward was 1.90%. The groups were significantly different with respect to the recipient age, the raw Model for End-Stage Liver Disease (MELD) score at the time of LT, the recipient body mass index (BMI), the retransplantation status, the operative time, the warm ischemia time, and the intraoperative transfusion requirements. A multivariate logistic regression analysis revealed that the raw MELD score at the time of LT, the operative time, the intraoperative transfusion requirements, the recipient age, the recipient BMI, and the absence of hepatocellular cancer/cholangiocarcinoma were significant predictors of ICU admission. In conclusion, we are reporting the largest single-center experience demonstrating the feasibility of bypassing an ICU stay after LT.

Heatstroke in the super-sized athlete.

We present a 16-year-old male athlete with hyperthermia, altered mental status, and respiratory distress during summer football practice. Multisystem organ failure ensued, which he survived. Malignant hyperthermia was suspected in this patient who had a history of rhabdomyolysis. Specific muscle contracture testing later eliminated this diagnosis. This case discusses the importance of rapid hydration with isonatremic fluid, aggressive cooling, and full support measures, including plasmapheresis, further diagnostic efforts to evaluate potential causes of rhabdomyolysis, and planning for physical and emotional rehabilitation.

Calibrated pneumoperitoneal venting to prevent N2O accumulation in the CO2 pneumoperitoneum during laparoscopy with inhaled anesthesia: an experimental study in pigs.

UNLABELLED: Nitrous oxide (N2O) accumulates in the CO2 pneumoperitoneum during laparoscopy when N2O is used as an adjuvant for inhaled anesthesia. This may worsen the consequences of gas embolism and introduce a fire risk. In this study, we quantified the pneumoperitoneal gas venting necessary to prevent significant contamination by inhaled N2O. Four domestic pigs (26-30 kg) were anesthetized and ventilated with 66% N2O in oxygen. A CO2 pneumoperitoneum was insufflated and maintained at a pressure of 12 mm Hg. Each animal underwent three experimental conditions, in random sequence, for 70 min each: 1) no pneumoperitoneal leak, 2) leak of 2 L every 10 min (12 L/h), and 3) leak of 4 L every 10 min (24 L/h). Every 10 min, pneumoperitoneal gas samples were analyzed for fractions (FPn) of N2O and CO2. Without leaks, FPnN2O increased continually and reached 29.58% +/- 3.15% at 70 min. With leaks of 2 and 4 L every 10 min (12 and 24 L/h), FPnN2O reached a plateau of <10% after 30 min. We conclude that calibrated pneumoperitoneal venting of 12 or 24 L/h is enough to prevent the constitution of potentially dangerous pneumoperitoneal gas mixtures if venting is constant. IMPLICATIONS: External venting calibrated at four or eight initial pneumoperitoneal volumes per hour with compensation by fresh CO2 is sufficient to prevent nitrous oxide buildup of more than 10% in the pneumoperitoneum during laparoscopy with inhaled general anesthesia if venting is constant.